U.S. patent number 9,220,271 [Application Number 12/155,985] was granted by the patent office on 2015-12-29 for non-dusty, free flowing, storage stable solid composition and a process for its preparation.
This patent grant is currently assigned to UPL Limited. The grantee listed for this patent is Sujata Dhondiram Desai, Prakash Mahadev Jadhav, Jaidev Rajnikant Shroff, Vikram Rajnikant Shroff. Invention is credited to Sujata Dhondiram Desai, Prakash Mahadev Jadhav, Jaidev Rajnikant Shroff, Vikram Rajnikant Shroff.
United States Patent |
9,220,271 |
Shroff , et al. |
December 29, 2015 |
Non-dusty, free flowing, storage stable solid composition and a
process for its preparation
Abstract
A solid water dispersible granular composition of pesticide
comprising up to 50% of at least one pesticide from pyrethroid
class, more particularly a highly viscous liquid pyrethroid
insecticide, permethrin, having the properties of excellent
dispersibility and suspensibility, as well as the process of
preparation of the composition are disclosed. Also the improved
storage stability, dispersibility and suspensibility properties are
discussed for this granular composition.
Inventors: |
Shroff; Jaidev Rajnikant
(Mumbai, IN), Shroff; Vikram Rajnikant (Mumai,
IN), Jadhav; Prakash Mahadev (Mumbai, IN),
Desai; Sujata Dhondiram (Dist. Satara, IN) |
Applicant: |
Name |
City |
State |
Country |
Type |
Shroff; Jaidev Rajnikant
Shroff; Vikram Rajnikant
Jadhav; Prakash Mahadev
Desai; Sujata Dhondiram |
Mumbai
Mumai
Mumbai
Dist. Satara |
N/A
N/A
N/A
N/A |
IN
IN
IN
IN |
|
|
Assignee: |
UPL Limited (Mumbai,
IN)
|
Family
ID: |
40132928 |
Appl.
No.: |
12/155,985 |
Filed: |
June 12, 2008 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20080312320 A1 |
Dec 18, 2008 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60944147 |
Jun 15, 2007 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A01N
53/00 (20130101); A01N 53/00 (20130101); A01N
25/08 (20130101); A01N 25/14 (20130101); A01N
25/30 (20130101); A01N 53/00 (20130101); A01N
2300/00 (20130101) |
Current International
Class: |
A01N
53/00 (20060101); A01N 25/08 (20060101); A01N
25/14 (20060101); A01N 25/30 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0127773 |
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Dec 1984 |
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EP |
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2003-95810 |
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Apr 2003 |
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JP |
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89/00079 |
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Jan 1989 |
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WO |
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90/07275 |
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Jul 1990 |
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WO |
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96/36226 |
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Nov 1996 |
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WO |
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2005/039288 |
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May 2005 |
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WO |
|
Other References
Permethrin MSDS accessed Nov. 16, 2011 from
http://msds.chem.ox.ac.uk/PE/permethrin.html, updated Sep. 5, 2003,
p. 1-3. cited by examiner .
Cyfluthrin MSDS accessed Nov. 16, 2011 from
http://pmep.cce.cornell.edu/profiles/extoxnet/carbaryl-dicrotophos/cyflut-
hrin-ext.html, updated Oct. 1995, p. 1-6. cited by examiner .
Tau-fluvalinate Crop Protection Dictionary,
http://sitem.herts.ac.uk/aeru/iupac/Reports/617.htm accessed Nov.
16, 2011, .COPYRGT. 2011, p. 1. cited by examiner .
Tefluthrin data sheet PPDB,
http://sitem.herts.ac.uk/aeru/iupac/Reports/617.htm accessed Nov.
16, 2011, updated Sep. 1, 2011, p. 1-7. cited by examiner .
Tralomethrin, Crop Protection Dictionary, .COPYRGT. 2011,
http://www.farmchemicalsinternational.com/cropprotection/cpd/?op=cpdprodu-
ctdetail&pid=400200 accessed Nov. 16, 2011, p. 1-2. cited by
examiner .
Fluvalinate MSDS,
http://pmep.cce.cornell.edu/profiles/extoxnet/dienochlor-glyphosate/flucy-
thrinate-ext.html accessed Nov. 16, 2011, published Sep. 1993, p.
1-5. cited by examiner .
Fenvalerate research document accessed via
http://pmep.cce.cornell.edu/profiles/insect-mite/fenitrothion-methylpara/-
fenvalerate/insect-extox-fenvalerate.html accessed Nov. 16, 2011,
p. 1-5. cited by examiner .
Esfenvalerate MSDS, published May 1994, accessed via
http://pmep.cce.cornell.edu/profiles/extoxnet/dienochlor-glyphosate/esfen-
valerate-ext.html accessed Nov. 16, 2011, p. 1-6. cited by examiner
.
Flucythrinate MSDS, published Sep. 1993, accessed via
http://pmep.cce.cornell.edu/profiles/extoxnet/dienochlor-glyphosate/flucy-
thrinate-ext.html accessed Nov. 16, 2011, p. 1-6. cited by examiner
.
Lambda-Cyhalothrin MSDS, revised 1996, accessed via
http://extoxnet.orst.edu/pips/lambdacy.htm accessed Nov. 16, 2011,
p. 1-5. cited by examiner.
|
Primary Examiner: Barham; Bethany
Assistant Examiner: Frazier; Barbara
Attorney, Agent or Firm: Yancy IP Law, PLLC
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit, under 35 U.S.C. 119(e), of
U.S. Provisional Application No. 60/944,147, the contents of which
are incorporated herein by reference.
Claims
We claim:
1. A free flowing water-dispersible dry granule formulation
comprising: (a) liquid permethrin in an amount of up to 50%
weight/weight adsorbed on a specific composition of inert fillers
of silica and inert clay kaolin, wherein the amount of silica is
10% weight/weight; (b) 2.75% weight/weight POE of alkyl ether
containing alkyl phenol ethoxylate and 8% weight/weight styrene
acrylic copolymer and optionally containing (c) inert formulation
adjuvants.
2. The free-flowing dry granular formulation according to claim 1,
wherein the said inert formulation adjuvants are selected from at
least one of additional surfactants, dispersing agents, defoamers,
wetting agents and binders.
3. The free-flowing dry granular formulation according to claim 2
wherein said additional surfactant is calcium dodecyl benzene
sulfonate.
4. The free-flowing dry granular formulation according to claim 2
wherein the defoamer is dimethyl polysiloxane.
5. The free-flowing dry granular formulation according to claim 2
wherein the wetting agent is sodium naphthalene sulfonate.
6. The free-flowing dry granular formulation according to claim 2
wherein the binder is selected from vinyl acetate homopolymer,
homopolymers of vinyl pyrrolidone and alkylated vinyl pyrrolidine
copolymers.
7. A formulation of free-flowing granules comprising 26.66%
weight/weight permethrin, precipitated silica in an amount of 10.0%
weight/weight, 2.75% weight/weight of POE of alkyl ether containing
alkyl phenol ethoxylate, 8% weight/weight styrene acrylic
copolymer, calcium dodecyl benzene sulfonate, dimethyl
polysiloxane, sodium naphthalene sulfonate and homopolymer of
vinylpyrrolidone.
Description
BACKGROUND OF THE INVENTION
1. Field of Invention
The proposed invention relates to a non dusty, free flowing,
storage stable solid composition. This invention particularly
relates to a non dusty, free flowing, storage stable solid
composition comprising of at least one pesticide from pyrethroid
class like cypermethrin, fenvalerate, permethrin,
alphacypermethrin, betacypermethrin, zetacypermethrin,
deltamethrin, cyfluthrin, low melting solid pyrethroids like
bifenthrin, lambda cyhalothrin, and/or bioresmethrin, more
particularly a high viscous liquid insecticide like permethrin.
More particularly, this invention relates to a stable composition
with improved properties of dispersibility and suspensibility
brought about by a combination of inert ingredients silica and
kaolin along with block copolymer of ethylene oxide and propylene
oxide in specific proportions. The present invention also relates
to a process of preparing the said composition.
2. Description of Related Art
Solid compositions like granules are mainly produced by methods
such as kneading, extrusion granulation, impregnation, coating etc.
Granules are more frequently applied to water surface or soil than
directly applied to target crops. After application to water
surface or soil, the active ingredient of granules
dissolves/disperses in water or vaporizes to reach its action sites
and displays the effect. It is therefore required that the same
water dispersibility and suspensibility as those at the time of
formulation are maintained even after long term storage.
Dry powdery (like wettable powder WP and others) composition has
disadvantages like presence of sediment at the bottom of dilution
tank, choking of nozzle while spraying, lumping during storage and
drift problem at the time of production, packing, transportation,
storage, handling, dilution and use.
Generally in liquid formulations like emulsifiable concentrates
(EC), soluble liquid (SL), Microemulsions (ME), and capsule
suspensions (CS) etc., the composition involves the use of organic
solvents like petroleum ether, hydrocarbon solvents, xylene,
isopropyl alcohol etc., which may cause further problems like
toxicity, irritation to human body and/or other associated problems
due to their physico-chemical properties like flash point, solvency
with other materials, flammable and reactive nature.
All liquid compositions (like emulsifiable concentrates EC and
others) which have been used in agriculture or veterinary
applications comprising liquid pyrethroids of concentrations more
than 20% suffer with high volatility due to volatile contents and
comprise flammable solvents. Organic solvents are most commonly
used as inert solvents. Suitable as liquid solvents, are aromatic
hydrocarbons, such as xylene, toluene or alkyl naphthalenes;
chlorinated aromatic hydrocarbons and chlorinated aliphatic
hydrocarbons, such as chlorobenzenes, methylene chloride; aliphatic
hydrocarbons, such as cyclohexane or paraffins, for example
petroleum fractions, mineral and vegetable oils, alcohols, such as
butanol or glycol as well as their ethers and esters, ketones, such
as acetone, methyl ethyl ketone, methyl isobutyl ketone or
cyclohexanone; strongly polar solvents, such as dimethylformamide
and dimethylsulphoxide. Some of these solvents are agriculturally
unacceptable, and need to be used in low or high concentrations to
produce formulations of desired strength, which can be diluted and
applied to the target areas to control pest effect. Selection and
use of the solvent is based on the solubility criteria for active
ingredients which sometimes require a single solvent or a
combination of solvents as per the type and strength of the
formulation product.
WO 9007275, discloses a dry herbicidal composition comprising a
water soluble salt of N-phosphonomethylglycine as a water
dispersible granule, water soluble granule, water dispersible
powder or water soluble powder. The composition comprises a water
soluble salt of N-phosphonomethylglycine and additionally one or
more liquid surfactants. This invention requires a preparation of
herbicidal water soluble salt during the process from its acid
derivative (which is solid in physical form) or a water soluble
salt (in solid physical form) as one of the main ingredients.
Prior art, Japanese patent 2003095810, discloses the wettable
granules comprising liquid pesticidal active ingredient, solvent,
emulsifier, dispersion agent and surfactant. This invention
requires the use of solvent so that the active ingredient gets
uniformly distributed over the inert ingredients.
Also, prior art EP127773, discloses tablet preparation of a
pesticidal composition comprising a pesticide, an emulsifier or
dispersing agent for the pesticide and a self disintegrating agent
capable of effervescing or swelling on being contacted with water.
The pesticide disclosed is a synthetic pyrethroid from 1-20% by
weight. This invention requires a self disintegrating agent which
is capable of effervescing or swelling on being contacted with
water. Methylene dichloride is used as a solvent for the active
ingredient and the simple mixing process is done to mix a solution
of above active ingredient and other ingredients comprising
emulsifier or dispersing agent, lubricants, surfactants and
antifoaming agents. Then the granule formation is done followed by
tablet formation.
The preparation of granules via an extrusion process is well known.
Most of the known processes extrude a premix of active material and
other ingredients under relatively high pressure, (and generally in
excess of 100 psi) and cut the spaghetti like extrudate into short
lengths. These may be subsequently dried. An alternative process is
disclosed in copending application PCT AU 88/00201 which uses low
pressure extrudation (<30 ps of a wet mix having relatively high
levels of water. This leads to an extrudate of low compactness
which readily breaks into small segments by gentle rolling or
tumbling action which also tends to round the ends of the granules.
Again these granules may be subsequently dried.
Granules may also be prepared by coating a core granule with an
absorbent coating of filler particles. A liquid active material may
then be loaded onto the surface layer of the granules. Such a
process is disclosed in NZ Patent 154,193 where the objective was
to produce granules with reduced absorptive properties compared to
granules prepared from minerals such as attapulgite. However these
granules are designed for direct application to soil, pastures or
other locus and as they have cores of particle size approximately
250 .mu.m they would not be suitable for use as WG as the granule
would not pass through the spray nozzle.
Also the basic method of preparing granules involves a preliminary
step of forming a wettable powder by blending the ingredients and
milling them to provide the desired particle size. The wettable
powder is then subsequently formed into granules by a range of
techniques including agglomeration, spray drying, or other means
such as pan granulation.
It is not always possible to achieve good dispersibility and shelf
life with all formulations especially with compositions where the
biologically active agent is in a liquid state and relatively high
levels of active agent are included in the granule. There is thus a
need for alternative granulation methods in order to enable a wider
spectrum of liquid pesticides to be formulated in an effective and
economical manner. Also there is a need for a non dusty, free
flowing, storage stable solid compositions comprising pyrethroid
type insecticides, more particularly semi viscous liquid pyrethroid
which results in a stable dispersion in presence of water. It is
well-known that the preparation of a DF formulation with liquid
active using the standard inert excipients is quite difficult for
over 10% active. The prior art teaches maximum of 25 EC and 25 WP
for actives like Permethrin but no DF formulations exist in the
market. The present invention takes care of all these problems of
dry WP, solid/granular, tablet/pellets formulations given in prior
art and provides for higher concentrations of liquid actives for DF
formulations.
BRIEF SUMMARY OF THE INVENTION
Silica and kaolin are traditionally known as inert fillers while
the block copolymer of ethylene oxide and propylene oxide is
traditionally known for its use as a surfactant. Surprisingly it
was found that when these were used in a definite ratio they
imparted properties of good suspensibility and dispersibility to
the formulation and also enabled in formulating high concentrations
of the liquid active ingredient into free-flowing granular form.
The solid compositions of the proposed invention have excellent
storage stability, dispersibility and suspensibility even after
comprising high concentrations of pesticides from pyrethroid
class.
In the present invention no solvent is used during granule
formulation so there is no risk of flammability and irritation to
the body. Generally, during formulation, organic solvents like
petroleum ether, isopropyl alcohol etc. are used which may cause
irritation to human body. Problems due to their flammable nature
are avoided in present invention by avoiding the use of organic
solvents. The inventors have discovered that the liquid active
ingredient when dissolved in the surfactant allows the adsorbed
active ingredient to disperse well at the time of dilution with
water. The inventors of the present invention have additionally
discovered the surprising effect of the synergistic action of the
combined use of inert ingredients silica and kaolin which normally
function only as fillers along with block copolymer of ethylene
oxide and propylene oxide which normally functions only as a
surfactant. When used together in a definite ratio, they imparted
properties of good suspensibility and dispersibility to the
formulation and also enabled in formulating high concentrations of
the liquid active ingredient into free-flowing granular form. In
addition, the present invention avoids excessive dust formation
during operation by skipping the grinding process.
The main objective of the proposed invention is to provide a non
dusty, free flowing, storage stable solid composition devoid of the
draw backs of the hitherto known composition.
Another objective of the proposed invention is to provide non
dusty, free flowing, storage stable solid composition having the
properties of storage stability, excellent dispersibility and
suspensibility.
Yet another objective of the proposed invention is to provide a non
dusty, free flowing, storage stable solid composition comprising at
least one pesticide from pyrethroid class like cypermethrin,
fenvalerate, permethrin, alphacypermethrin, betacypermethrin,
zetacypermethrin, deltamethrin, cyfluthrin, bifenthrin,
lambda-cyhalothrin, and/or bioresmethrin.
Yet another objective of the proposed invention is to provide non
dusty, free flowing, storage stable solid composition having the
properties of excellent dispersibility and suspensibility using at
least a liquid surfactant selected from polyoxyethlene alkyl ether
group.
Another objective of the proposed invention is to provide non
dusty, free flowing, storage stable solid composition having the
properties of excellent dispersibility and suspensibility in solid
form preferably in water dispersible granular form.
Yet another objective of the proposed invention is to provide a
process for the preparation of non dusty, free flowing, storage
stable solid composition which is a relatively inexpensive and
environmentally safe.
Yet another objective of the proposed invention is to provide a
process for the preparation of non dusty, free flowing, storage
stable solid composition in water dispersible granular form which
are not prone to dust generation while filling in bags and
transportation, thereby avoiding polluting the environment.
Another objective of the proposed invention is to provide a process
for the preparation of non dusty, free flowing, storage stable
solid composition in water dispersible granular form by using the
liquid pesticide.
Yet another objective of the proposed invention is to provide a
process for the preparation of non dusty, free flowing, storage
stable solid composition in water dispersible granular form by
using at least a liquid pesticide and at least one liquid
surfactant.
Yet another objective of the proposed invention is to provide a
process for the preparation of non dusty, free flowing, storage
stable solid composition without using any solvents.
The above mentioned objectives of the proposed invention have been
achieved by our sustained R & D due to our finding that in
solid composition comprising pyrethroids, the use of liquid
surfactants selected from polyoxyethlene alkyl ether group and when
this composition is coated on a mixture of Kaolin and precipitated
silica as an inert filler in selected ratio provides good
dispersibility and suspensibility to the resulting solid
composition. Also kaolin, which normally acts as inert filler, acts
as a carrier in the composition of the present invention due to
adsorption process. In addition to this, silica, which is normally
used as an adsorbent, functions as an anticaking agent.
Accordingly, the proposed invention provides a non dusty, free
flowing, storage stable solid composition which comprises a mixture
of kaolin and precipitated silica having a coating of a composition
comprising at least one pesticide selected from pyrethroid class
like cypermethrin, fenvalerate, permethrin, alphacypermethrin,
betacypermethrin, zetacypermethrin, deltamethrin, cyfluthrin,
bifenthrin, lambda-cyhalothrin, and/or bioresmethrin and at least
one liquid surfactant selected from polyoxyethlene alkyl ether
group.
According to another aspect of the proposed invention, there is
provided a process for the preparation of a non dusty, free
flowing, storage stable solid composition which comprises:
(i) mixing an active ingredient selected from at least one
pesticide selected from pyrethroid class like cypermethrin,
fenvalerate, permethrin, alphacypermethrin, betacypermethrin,
zetacypermethrin, deltamethrin, cyfluthrin, bifenthrin,
lambda-cyhalothrin, and/or bioresmethrin with at least one liquid
nonionic surfactant selected from polyoxyethlene alkyl ether group
and one anionic surfactant selected from salt of alkyl aryl
sulphonate group (i.e. calcium salt of dodecyl benzene sulphonate)
to obtained a liquid mixture;
(ii) mixing the powder of kaolin, precipitated silica, wetting
agent, dispersing agent, and a binder;
(iii) adding the liquid mixture obtained in step (i) to a mixing
vessel containing the powder prepared described in step (ii);
(iv) mixing thoroughly the ingredients of step (iii);
(v) granulating the resulting mixture obtained in step (iv);
(vi) sieving, if required, to obtain the desired sizes of the solid
composition; and
(vii) drying, if required, the resulting solid composition.
DETAILED DESCRIPTION OF THE INVENTION
The present invention is broadly related to free-flowing solid
compositions of high concentrations of liquid pyrethroid pesticides
with good suspensibility and dispersability properties. These
properties are achieved by the combined use of inert ingredients
silica and kaolin along with polyoxyethlene alkyl ether or block
copolymer of ethylene oxide and propylene oxide. Silica and kaolin
are traditionally known as fillers and block copolymer of ethylene
oxide and propylene oxide is traditionally known for its use as a
surfactant for liquid compositions. Surprisingly it was found that
when the block copolymer of ethylene oxide and propylene oxide when
combined with silica and kaolin in a definite ratio, imparted
properties of good suspensibility and dispersibility to the
formulation and also enabled in formulating high concentrations of
the liquid active ingredient into free-flowing granular form.
Granules prepared by using other solid surfactants such as sodium
naphthalene sulfonate, naphthalene formaldehyde condensate, castor
oil ethoxylates and like which are known for their use in solid
granular formulations, were not able to provide good dispersability
to the final composition. Even liquid surfactants like castor oil
ethoxylate and alkyl phenol ethoxylate did not impart the required
dispersibility and suspensibility to the high active pesticidal
compositions of the present invention.
Experiments were conducted to select and evaluate the inert fillers
of at least some oil absorption value of 75 to make the dry
flowable particulates of up to 50% liquid active. Inert clay kaolin
and silica were evaluated individually for their effect on granule
formation.
Kaolin has a liquid holding capacity (LHC) or oil absorbtion of
10-20%;
TABLE-US-00001 TABLE 1 Effect of various concentrations of inert
clay kaolin on granulation of various concentrations of active
ingredient. Sr No % active Kaolin % Observations 1 0.11 80.56 (A) 2
0.53 79.64 (A) 3 5.32 73.35 (A) 4 26.66 46.01 (B) 5 31.92 40.75 (C)
6 37.24 35.43 (C) 7 42.56 30.11 (C) 8 47.88 18.79 (C) 9 53.20 13.47
(C) (A) Good granules with bulk density ranging from 0.650 to 0.720
g/ml and wet sieve test: 99% passing through 75.mu. (200 BSS). (B)
Slightly soft sticky granules with bulk density ranging from 0.543
to 0.589 g/ml and wet sieve test: 89% passing through 75.mu. (200
BSS). (C) Soft and Sticky granules with bulk density ranging from
0.513 to 0.532 g/ml and wet sieve test: 78% passing through 75.mu.
(200 BSS).
Inert filler silica with liquid holding capacity (LHC) or oil
absorption of 120 to 180% was evaluated and following observations
were made.
TABLE-US-00002 TABLE 2 Effect of various concentrations of silica
on granulation of various concentrations of active ingredient.
Ratio Sr No % age active Silica % Observations % active:% silica 1
0.1064 2 (A) 1:18.796 2 1.064 3 (A) 1:2.819 3 5.32 4 (A) 1:0.752 4
10.64 5 (A) 1:0.469 5 15.96 7 (A) 1:0.439 6 26.66 10 (A) 1:0.376 7
37.24 12 (A) 1:0.322 8 42.56 12 (A) 1:0.282 9 47.88 20 (B) 1:0.418
10 53.20 20 (B) 1:0.376 (A) Good granules with bulk density ranging
from 0.640 to 0.710 g/ml and wet sieve test: 99% passing through
75.mu. (200 BSS). (B) Soft and Sticky granules with bulk density
ranging from 0.510 to 0.538 g/ml and wet sieve test: 78% passing
through 75.mu. (200 BSS).
The above table indicates that individual clay alone is not able to
help in good granule formation. Also random selection of a mixture
could not be used.
Individual clays/inerts were evaluated for their oil absorbtion or
liquid holding capacity and compared with reported values.
Clay minerals of the montmorillonite group, based on a three layer
structure comprising two tetragonal layers of SiO.sub.4 sandwiching
an octagonal layer of AlO.sub.6 between them, and a plurality of
such basic three-layer structures were also evaluated.
Montmorillonite has a liquid holding capacity (LHC) or oil
absorption of 30-70%.
TABLE-US-00003 TABLE 3 Effect of various concentrations of inert
clay montmorillonite on granulation of various concentration of
active ingredients. No. Clay - Montmorillonite % age active
Observations 1 60.46 15.96 A 2 46.82 26.60 B 3 41.5 31.92 B 4 30.86
42.56 B 5 14.22 53.20 B (A) Good granules with bulk density ranging
from 0.635 to 0.715 g/ml and wet sieve test: 99% passing through
75.mu. (200 BSS). (B) Soft and Sticky granules with bulk density
ranging from 0.505 to 0.550 g/ml and wet sieve test: 75% passing
through 75.mu. (200 BSS).
Bentonite is a naturally occurring, white calcium clay. Due to its
thixotropic properties, bentonite functions as a thickening and/or
suspension agent in water and solvent paints.
TABLE-US-00004 TABLE 4 Effect of various concentrations of inert
clay Bentonite on granulation of various concentration of active
ingredients. Clay - Bentonite % age active Observations 1 60.46
15.96 A 2 46.82 26.60 B 3 36.18 37.24 B 4 30.86 42.56 B 5 19.54
47.88 B (A) Good granules with bulk density ranging from 0.642 to
0.711 g/ml and wet sieve test: 99% passing through 75.mu. (200
BSS). (B) Soft and Sticky granules with bulk density ranging from
0.517 to 0.548 g/ml and wet sieve test: 77% passing through 75.mu.
(200 BSS).
It is thus seen that not any individual clay can be used. Also
random selection of mixture cannot be used.
TABLE-US-00005 TABLE 5 Comparision of oil absorbtion or liquid
holding capacity of Reported LHC cc/gram with Evaluated LHC cc/gram
Reported LHC Evaluated LHC cc/gram cc/gram Kaolin 30-70 10-20
Silica 180-200 120-140 Bentonite 40-70 10-15 Montmorillonite 30-70
10-20
Then kaolin and silica combination was evaluated for their combined
LHC and observations were tabulated.
TABLE-US-00006 TABLE 6 Ratio of Silica + Kaolin mixture for
absorption of liquid active in higher concentrations. Ratio of % %
Active:% silica + Sr No % active silica:kaolin Observations Kaolin
1 0.1 2 + 81.31 (A) 1:782.9 2 1.064 3 + 79.36 (A) 1:77.41 3 5.32 4
+ 74.10 (A) 1:14.68 4 10.64 5 + 67.78 (A) 1:6.840 5 15.96 7 + 60.48
(A) 1:4.228 6 26.60 10 + 46.82 (A) 1:2.136 7 37.24 12 + 36.18 (A)
1:1.294 8 42.56 12 + 30.86 (A) 1:1.007 9 47.88 20 + 19.54 (B)
1:0.826 10 53.20 20 + 14.22 (B) 1:0.643 (A) Good granules with bulk
density ranging from 0.649 to 0.719 g/ml and wet sieve test: 99%
passing through 75.mu. (200 BSS). (B) Soft and Sticky granules with
bulk density ranging from 0.520 to 0.545 g/ml and wet sieve test:
78% passing through 75.mu. (200 BSS). Best ratio(s) of
silica:kaolin are placed in between 1:1 to 1:40 for formation of
good granules.
The above chosen combination of inerts was used to adsorb the
liquid active but it was found that the limitation of the DF
formulation was its non-dispersibility and non-suspensibility.
Traditionally known surfactants were tried out to improve the
non-dispersibility.
TABLE-US-00007 TABLE 7 Composition using traditional Solid
surfactants Sr. No. Ingredients A B C 1 Permethrin Technical 26.60
26.60 26.60 2. Sodium naphthalene 0.00 8.00 0.00 formaldehyde
condensate 3 Dioctyl sulfosuccinate 0.00 0.00 8.00 4 Styrene
acrylic copolymer 8.00 0.00 0.00 5 Kaolin 46.05 45.65 46.65 6
Sodium Naphtalene 5.00 5.00 5.00 sulphonate 7 Dimethyl poly
siloxane 30% 0.50 0.50 0.50 emulsion 8 Poly vinyl pyrrolidone 0.25
0.25 0.25 Comments: Suspensibility & Suspensibility &
Suspensibility & Dispersibility Dispersibility Dispersibility
of of granules of granules granules are very are very low. are very
low. low.
All the above solid surfactants when used individually failed to
impart the requisite dispersibility. In fact none of the solid
surfactants worked alone or in mixtures.
Even the traditional liquid surfactants were unable to give the
required dispersibility and suspensibility.
TABLE-US-00008 TABLE 8 Effect of traditional liquid surfactants on
dispersibility and suspensibility of the DF composition. Sr. No.
Ingredients A B C 1 Permethrin Technical 26.60 26.60 26.60 2.
Ethoxylated caster oil 40 2.75 0.00 0.00 moles 3 Calcium dodecyl
benzene 0.85 1.00 0.75 sulphonate 4 Precipitated silica 10.00 10.00
10.00 5 Kaolin 46.05 45.65 46.65 6 Sodium Naphtalene 5.00 5.00 5.00
sulphonate 7 Styrene acrylic copolymer 8.00 8.00 8.00 8 Dimethyl
poly siloxane 30% 0.50 0.50 0.50 emulsion 9 Poly vinyl pyrrolidone
0.25 0.25 0.25 10 Ethoxylated nonyl phenol 0.00 3.00 0.00 9.5 moles
11 Ethoxylated sorbitan 0.00 0.00 2.25 monooleate 20 moles
Comments: Suspensibility & Suspensibility & Suspensibility
& Dispersibility Dispersibility Dispersibility of granules of
granules of granules are very low. are very low. are very low.
Further experiments were conducted with Polyoxyethylene alkyl ether
also called EO/PO surfactant normally unused in DF formulations.
Surprising results were obtained with the said surfactant with
improved dispersibility and suspensibility.
TABLE-US-00009 TABLE 9 Effect of various concentrations of EO/PO on
granule quality. Quantity of Ratio of Sr. No. % Active EO/PO Active
%:EO/PO % Comments 1 0.1064 1.50 1:14.09 (A) 2 1.064 1.70 1:1.598
(A) 3 5.32 1.75 1:0.329 (A) 4 10.64 2.00 1:0.188 (A) 5 15.96 2.50
1:0.157 (A) 6 26.60 2.75 1:0.103 (A) 7 37.24 3.50 1:0.094 (A) 8
42.56 3.75 1:0.088 (A) 9 47.88 4.00 1:0.084 (B) 10 53.20 4.50
1:0.085 (B) (A) Good dispersibility & suspensibility;
dispersibility = 96-98%; suspensibility = 88-90%. (B) Soft &
slightly sticky granules with decreasing dispersibility &
suspensibility; dispersibility = 80-85%; suspensibility =
74-78%.
The working range of EO/PO surfactants was found to be optimal
between 1.5 to 3.75%. Within this range good emulsification of the
liquid active ingredient was observed.
To further improve the dispersibility and suspensibility of silica
and kaolin, styrene acrylic co-polymer was considered.
TABLE-US-00010 TABLE 10 Effect of various concentrations of Styrene
acrylic copolymer on granule quality. Quantity of styrene acrylic
Sr. No. % Active Ratio of Silica:Kaolin copolymer Comments 1 0.1064
1:40.655 5 (A) 2 1.064 1:26.45 6 (A) 3 5.32 1:18.525 7 (A) 4 10.64
1:13.556 7 (A) 5 15.96 1:8.637 8 (A) 6 26.60 1:4.682 8 (A) 7 37.24
1:3.015 9 (A) 8 42.56 1:2.572 10 (A) 9 47.88 1:0.977 11 (B) 10
53.20 1:0.711 13 (B) (A) Good dispersibility & suspensibility;
dispersibility = 96-98%; suspensibility = 88-90%. (B) Soft &
slightly sticky granules with decreasing dispersibility &
suspensibility; dispersibility = 80-85%; suspensibility =
74-78%.
5 to 10% of Styrene acrylic copolymer was found to give good
dispersibility and suspensibility for the optimal ratio of silica
and kaolin. A combination of EO/PO with styrene copolymer was
studied for further improvement of the granule dispersibility and
suspensibility.
TABLE-US-00011 TABLE 11 Effect of a combination of various
concentrations of EO/PO and Styrene acrylic copolymer. Quantity of
Ratio of EO/PO/Styrene Sr. No. % Active Silica:Kaolin acrylic
copolymer Observations 1 0.1064 1:40.655 1.50/5 (A) 2 1.064 1:26.45
1.70/6 (A) 3 5.32 1:18.525 1.75/7 (A) 4 10.64 1:13.556 2.00/7 (A) 5
15.96 1:8.637 2.50/8 (A) 6 26.60 1:4.682 2.75/8 (A) 7 37.24 1:3.015
3.50/9 (A) 8 42.56 1:2.572 3.75/10 (A) 9 47.88 1:0.977 4.00/11 (B)
10 53.20 1.0.711 4.50/13 (B) (A) Good dispersibility &
suspensibility; dispersibility = 98-99%; suspensibility = 90-91%.
(B) Soft & slightly sticky granules with decreasing
dispersibility & suspensibility; dispersibility = 82-85%;
suspensibility = 75-77%.
Surprisingly it was observed that granules with emulsifiable
concentrate (EC) provided the requisite dispersibility, however the
granules were unable to be formed. This surprising observation of
use of emulsifier with the above combination of kaolin and silica
provided the most unobvious results of free-flowing dispersible
granules at high concentrations of liquid actives.
Polyoxyethlene alkyl ether, the block copolymer of ethylene oxide
and propylene oxide is a surfactant having a comparable hydrophilic
chains length than those of most other surfactants and they are
flexible. They bind water avidly by hydrogen bond acceptor
interactions with ether-linked oxygen. These long, strongly
hydrated flexible chains are relatively incompressible and form a
barrier to hydrophobic surfaces approaching one another. As
emulsifying and/or dispersing agents there are suitable: for
example non-ionic and anionic emulsifiers, such as
polyoxyethylene-fatty acid esters, polyoxyethylene-fatty alcohol
ethers, for example alkylaryl polyglycol ethers, alkylsulphonates,
alkylarylsulphonates, alkylsulphates, arylsulphonates, their
hydrolysis products & salts. More precisely, the use of
polyoxyethlene alkyl ether in this case helped to provide a solid
composition with at least 60% dispersibility and suspensibility
despite high concentrations of viscous liquid pesticide. A mixture
prepared by adding active ingredient with at least one
polyoxyethylene alkyl ether surfactant helps to cover the treated
surface area uniformly.
By the term "wetting agent" is meant a compound which permits the
granule to rapidly wet into the water, and, more precisely, a
compound which, when mixed in selected proportions with
agriculturally active compounds, in the form of granules, give a
mixture which has a wettability time of less than 2 minutes. This
wetting agent can be an ionic or non-ionic agent or a mixture of
such surface-active agents.
Compounds which are usable as wetting agents and which can be cited
are, for example, the alkylarylsulphonate-type salts, in particular
the alkali metal alkylnaphthalene sulphonates, the salts of
polycarboxylic acids, polycondensates of ethylene oxide with fatty
alcohols or with fatty acids or with fatty amines, or substituted
phenols (in particular alkylphenols or arylphenols), and salts of
esters of sulphosuccinic acids.
By the term "dispersing agent" is meant a compound which ensures
that the particles remain suspended in the application mixture and
which allows rapid disintegration of the granule in the water. More
precisely, by dispersing agent is meant a compound which, when
intimately mixed in selected proportions with agriculturally active
compounds, in the form of granules, gives a mixture which has a
suspensibility of more than 50%. The dispersing agent can be an
ionic or non-ionic agent or a mixture of such surface-active
agents.
As compounds which are suitable as dispersing agents there may be
cited, for example, arylsulphonate-type polymers, in particular the
alkali metal polynaphthalenesulphonates obtained by condensation of
(alkyl)arylsulphonates with formaldehyde, the lignosulphonates, the
polyphenylsulphonates, salts of polyacrylic acids, salts of
lignosulphonic acids, salts of phenolsulphonic acids or
naphthalenesulphonic acids, taurine derivatives (in particular
alkyltaurates), phosphoric esters of alcohols or of polycondensates
of ethylene oxide and phenols, esters of fatty acids and polyols,
and the derivatives of the preceding compounds which have sulphate,
sulphonate and phosphate functions.
The term "binders" refers to all binders which are suitable for
solid compositions such as in water-dispersible solid formulations.
The following are preferably suitable in this context:
methylcellulose, sugars, dextrin, starch, alginates, glycols,
polyvinyl pyrrolidone, ligninsulphonate, gum arabic, polyvinyl
alcohol and polyvinyl acetate, water, or a solution containing
dissolved wetting and dispersing agents.
In the step additional inert fillers may be used. Such "inert
fillers" refer to a solid organic or inorganic material, natural or
synthetic, with which the active substance is combined so as to
facilitate the specific application of the granulated product. This
filler is therefore generally inert and acceptable. The filler can
be selected for example from amongst clay, diatomaceous earth,
kaolin clay, the natural or synthetic silicates, silica,
precipitated silica, soluble or insoluble mineral salts, organic
derivatives, and polysaccharide compounds such as starch,
cellulose, aliginates, soluble mineral salts, sugars and lactose or
a combination thereof. The inert fillers which can be used are
hydrophilic fillers which have a disintegrating action, that is to
say which facilitate the adsorption as well as absorption of active
ingredient and also facilitate the dispersion and suspension of the
granule according to the invention in the presence of water.
Besides the product used for granulation the product (first
compound) may contain at least a second active compound of a type
which differs from the first compound, which has the aim of
widening the spectrum of the first one. In the case of agro
chemicals used the first and second compound may be a contact
pesticide, which act by contact with the plants/pests. This second
agent may be present in the solid composition prepared by the
process of the proposed invention in an amount between 0.1 to
40.0%. The first agricultural compound may be present in
quantities, preferably between 0.1 to 50.0%, the other ingredients
in the end product being the wetting agent, dispersing agent and
inert fillers. Besides the above-described ingredients the
granulated product may also contain 10.0 to 99.80% of suitable
additives, such as antifoams, sequestering agents, stabilizers,
penetrating agents, adhesives, anti-caking agents, colorants, and
others.
The process of the proposed invention is generally carried out
starting with the mixing of an active ingredient, with at least
polyoxyethlene alkyl ether surfactants to obtain a liquid mixture.
There after the preparation of the powders of wetting agent,
dispersing agent, binder and inert fillers by mixing is done. This
mixing of the powders may be done in suitable mixers.
According to the proposed invention adding of the liquid mixture is
done over the powder prepared. After complete addition of the
liquid mixture these ingredients are mixed thoroughly to obtain a
homogenous powdery mixture. This powdery mixture can also be
considered as one of the forms of invented solid composition which
is in the form of powder. If the granulated product is required
then this is achieved by continuing the mixing for an additional
time, after spraying was over. Thereafter granulation of the
mixture is performed by using water as a granulating liquid. Then
the fine particles are separated from oversized particles. If
required, the fine and oversized particles are recycled and drying
of the granules is done, as required, in a drier like equipment
like Fluidized bed dryer to a moisture content below 2% w/w. Again
sieving of the dried granules is done by using vibratory sieve to
finally remove any fine and or oversize granules. The fine and the
oversize separated particles can be recycled to the granulator
after drying and grinding to suitable particle size.
According to the proposed invention, the powder taken in the
container of the apparatus is mixed with granulating liquid, from 1
to 30%, preferably 5 to 15% of the required quantities. This
moistened powder has the consistency of a non drifting dust. This
is further processed in the container with the addition of
remaining quantity of the granulating liquid in such a way as to
obtain the granulated product.
The granules prepared by the process according to the proposed
invention are therefore concentrated products. The granulated
agricultural products which are prepared according to the process
of the proposed invention which are diluted by the agriculturalists
in containers which contain water for application. These diluted
mixtures are usually applied at 5 to 1000 l/ha.
The use of solvents such as petroleum solvents, methylene
dichloride and the like resulted in phase separation on dilution
with water. Surprisingly it was possible to formulate the high
dispersible and suspensible granules even without the use of
solvents by careful combination of selected liquid surfactants
along with a specific composition of inert ingredients on which the
liquid active is adsorbed.
The compositions of the present invention actually fall into the
category of dispersible granules comprising an intrinsic
combination of granule, surfactant/s, oil (the active ingredient
which is in the form of a viscous liquid is considered as the oil
which is emulsified) and the active ingredient which is adsorbed on
the solid inert ingredient/s. Thus it was possible to produce
free-flowing dispersible granules even without the use of solvents
and thus eliminate the possibility of flammability during handling,
processing, storage and transportation and irritation to skin of
human body and make an environment friendly composition.
In the present invention, active ingredients used may be in the
range of 0.1-50% by weight of composition. The solid composition
has a long activity and quick-acting property with residual
effectiveness and improvement in stickiness, fluidity and
bulkiness, also from the view point of physical properties of the
formulation.
The details of the invention are given in the Examples given below
which are given only to illustrate the invention and hence they
should not be construed to limit the scope of the invention
Example 1
The composition was designed to test the effect of solid
surfactants such as Sodium naphthalene formaldehyde condensate and
Sodium naphthalene sulfonate on the performance of the
granules.
TABLE-US-00012 Ingredients Function % w/w Permethrin Technical
Active Ingredient 26.66 Sodium naphthalene Surfactant 4.00
formaldehyde condensate Sodium naphthalene sulfonate Wetting agent
2.00 Tri sodium phosphate Stabilizer 1.00 Sodium stearate Lubricant
1.00 Poly vinyl alcohol Binder 0.50 Precipitated Silica Inert
filler 18.84 Kaolin Inert filler 46.01 Total 100.00
It was observed that the mixture became wet and granules obtained
were soft. The granules gave 1 ml sediment in 5 minutes after
dilution with water, therefore giving low dispersibility and
suspensibility. It was further observed that even after milling of
premix to reduce the particle size, the low dispersibility and
suspensibility did not improve. The formulation was found to be
unacceptable.
Example 2
The composition of Example 1 which resulted in granules of sticky
nature was modified to increase the quantity of silica to 46.01% to
improve the flowability of the granules.
TABLE-US-00013 Ingredients Function % w/w Permethrin Technical
Active Ingredient 26.66 Sodium naphthalene Surfactant 4.00
formaldehyde condensate Sodium naphthalene sulfonate Wetting agent
2.00 Tri sodium phosphate Stabilizer 1.00 Sodium stearate Lubricant
1.00 Poly vinyl alcohol Binder 0.50 Precipitated Silica Inert
filler 46.01 Kaolin Inert filler 18.84 Total 100.00
The above composition was not workable because of decreased
dispersibility of granules. The high silica content was able to
decrease the wettiness of the granules, but was unable to provide a
suitable degree of dispersibility. In fact the dispersibility was
found to be even lower than earlier example.
Example 3
The composition was modified to include organic solvents in the
formulation.
TABLE-US-00014 Ingredients % w/w Permethrin Technical 26.66 POE of
alkyl ether containing alkyl 2.75 phenol ethoxylate Calcium dodecyl
benzene sulfonate 0.83 Petroleum solvent 10.00 Styrene acrylic
copolymer 8.00 Dimethyl polysiloxane, 30% emulsion 0.50 Polyvinyl
pyrrolidone 0.25 Precipitated Silica 10.00 Kaolin 36.01 Total
100.00
The above composition was unable to provide the required degree of
dispersibility and suspensibility to the granules.
Example 4
Experimental trials were further conducted for determining the
optimal quantity of POE of alkyl ether containing alkyl phenol
ethoxylate in the formulation. All parameters remaining the same,
Composition A contained 1.75% of POE of alkyl ether containing
alkyl phenol ethoxylate, Composition B contained 2.75% of POE of
alkyl ether containing alkyl phenol ethoxylate and Composition C
contained 3.75% of POE of alkyl ether containing alkyl phenol
ethoxylate.
TABLE-US-00015 Ingredients A B C Permethrin Technical 26.66 26.66
26.66 POE of alkyl ether containing alkyl 1.75 2.75 3.75 phenol
ethoxylate Calcium dodecyl benzene sulfonate 0.83 0.83 0.83
Precipitated Silica 10.00 10.00 10.00 Sodium naphthalene sulfonate
5.00 5.00 5.00 Styrene acrylic copolymer 8.00 8.00 8.00 Dimethyl
polysiloxane, 30% emulsion 0.50 0.50 0.50 Homopolymer of
Vinylpyrrolidone 0.25 0.25 0.25 Kaolin 52.01 46.01 40.01 Total
100.00
From the above trials, it was observed that composition A and C
showed reduced emulsification of permethrin. Composition B showed
optimal results and was considered as most appropriate for the
composition.
Composition B was tested for required parameters the following
results were observed:
TABLE-US-00016 Suspensibility (% w/w): 87.50 Dispersibility (%
w/w): 72 Wettability (sec.): 7 Dustiness (% w/w): 0.20
Example 5
In order to arrive at an optimal concentration of silica in the
composition, three compositions were designed and designated as A,
B and C with variations in amounts of silica.
TABLE-US-00017 Ingredients A B C Permethrin Technical 26.66 26.66
26.66 POE of alkyl ether containing alkyl 2.75 2.75 2.75 phenol
ethoxylate Calcium dodecyl benzene sulfonate 0.83 0.83 0.83
Precipitated Silica 5.00 10.00 15.00 Sodium naphthalene sulfonate
5.00 5.00 5.00 Styrene acrylic copolymer 8.00 8.00 8.00 Dimethyl
polysiloxane, 30% emulsion 0.50 0.50 0.50 Homopolymer of
Vinylpyrrolidone 0.25 0.25 0.25 Kaolin 51.01 46.01 41.01 Total
100.00
Composition A with 5% silica resulted in slightly sticky granules
having average suspensibility. Composition C resulted in granules
with good flowability but reduced suspensibility. Composition B
with 10% silica resulted in granules with very good flowability and
suspensibility. The optimum concentration of 10% was selected.
Example 6
Experimental trials were conducted using lactose as a soluble
carrier instead of kaolin to improve suspensibility and
dispersibility,
TABLE-US-00018 Ingredients Function % w/w Permethrin Technical
Active Ingredient 26.66 POE of alkyl ether containing alkyl
Surfactant 2.75 phenol ethoxylate Calcium dodecyl benzene sulfonate
Surfactant 0.83 Precipitated Silica Inert filler 10.00 Sodium
naphthalene sulfonate Wetting agent 5.00 Styrene acrylic copolymer
Dispersant 8.00 Dimethyl polysiloxane, 30% emulsion Defoamer 0.50
Homopolymer of Vinylpyrrolidone Binder 0.25 Lactose Inert filler
46.01 Total 100.00
The resultant granules were sticky in nature with reduced
flowability and could not be further processed.
Example 7
Trials were conducted using varying amounts of styrene acrylic
co-polymer which is crucial for suspending the inert carrier silica
and kaolin. Composition A contains 5% Styrene acrylic copolymer;
composition B contains 8% Styrene acrylic copolymer and composition
C contains 13% Styrene acrylic copolymer.
TABLE-US-00019 Ingredients A B C Permethrin Technical 26.66 26.66
26.66 POE of alkyl ether containing alkyl 2.75 2.75 2.75 phenol
ethoxylate Calcium dodecyl benzene sulfonate 0.83 0.83 0.83
Precipitated Silica 10.00 10.00 10.00 Sodium naphthalene sulfonate
5.00 5.00 5.00 Styrene acrylic copolymer 5.00 8.00 13.00 Dimethyl
polysiloxane, 30% emulsion 0.50 0.50 0.50 Homopolymer of
Vinylpyrrolidone 0.25 0.25 0.25 Kaolin 55.01 46.01 35.01 Total
100.00
It was observed that for composition A there was a drop in
suspensibility. Composition B had ideal suspensibility. In
composition C excess foaming was observed. It was concluded that 8%
Styrene acrylic copolymer was optimal for attaining desirable
suspensibility of the formulation.
Example 8
Step I
Permethrin Technical (26.66% w/w), POE of alkyl ether containing
alkyl phenol ethoxylate (2.75% w/w), Calcium dodecyl benzene
sulfonate (0.83% w/w) and Dimethyl polysiloxane, 30% emulsion (0.5%
w/w) were weighed and transferred in a vessel having homogenizer to
handle moderate viscous liquid. The mixture was homogenized for 30
min. at 30-400.degree. C.
Step II
Styrene acrylic copolymer (8.00% w/w), Sodium naphthalene sulfonate
(5.00% w/w), pre ground Kaolin (46.01% w/w), Homopolymer of
Vinylpyrrolidone (0.25% w/w), Precipitated Silica (10.00% w/w) are
transferred in appropriate blender having spray arrangement. The
mixture was blended for 10 min. along with the spraying of the
liquid mixture of step I over it. The blending was continued for
further 10 min. after spraying was completed.
Step III
Using appropriate granulator and mechanized water spray system, the
product of step II was granulated to get non-dusty, free flowing,
storage stable granules.
The ingredients used are given below in table 1.
The end product of each lot of granulated wet granules was first
conditioned. The fines separated were re-cycled to granulator.
Oversized granules were dried and ground to suitable particle size
to re-cycle on granulator.
The desired sized wet/conditioned granules were dried using
equipment like fluidized bed drier to moisture content below 2%
w/w.
The dried granules were sieved by using vibratory sieve, the fines
and oversized separated were recycled in granulator after drying
and grinding to suitable particle size. The representative
composite sample of dried and required dust free granules was
analyzed.
TABLE-US-00020 TABLE 1 Ingredients Function % w/w Permethrin
Technical Active Ingredient 26.66 POE of alkyl ether containing
alkyl Surfactant 2.75 phenol ethoxylate Calcium dodecyl benzene
sulfonate Surfactant 0.83 Precipitated Silica Inert filler 10.00
Sodium naphthalene sulfonate Wetting agent 5.00 Styrene acrylic
copolymer Dispersant 8.00 Dimethyl polysiloxane, 30% emulsion
Defoamer 0.50 Homopolymer of Vinylpyrrolidone Binder 0.25 Kaolin
Inert filler 46.01 Total 100.00
The same procedure as given in example 1 was repeated with
different % w/w of Permethrin technical, Precipitated Silica, and
Kaolin to get granules with improved storage stability,
suspensibility, dispersibility as well as wettability of the
granules.
The % w/w for the ingredients involved in different processes is
given below: (Examples 2-Examples 9)
Example 9
TABLE-US-00021 Ingredients Function % w/w Permethrin Technical
Active Ingredient 0.11 POE of alkyl ether containing alkyl
Surfactant 2.75 phenol ethoxylate Calcium dodecyl benzene sulfonate
Surfactant 0.83 Precipitated Silica Inert filler 2.0 Sodium
naphthalene sulfonate Wetting agent 5.00 Styrene acrylic copolymer
Dispersant 8.00 Dimethyl polysiloxane, 30% emulsion Defoamer 0.5
Homopolymer of Vinylpyrrolidone Binder 0.25 Kaolin Inert filler
80.56 Total 100.00
Example 10
TABLE-US-00022 Ingredients Function % w/w Permethrin Technical
Active Ingredient 0.53 POE of alkyl ether containing alkyl
Surfactant 2.75 phenol ethoxylate Calcium dodecyl benzene sulfonate
Surfactant 0.83 Precipitated Silica Inert filler 2.5 Sodium
naphthalene sulfonate Wetting agent 5.00 Styrene acrylic copolymer
Dispersant 8.00 Dimethyl polysiloxane, 30% emulsion Defoamer 0.5
Homopolymer of Vinylpyrrolidone Binder 0.25 Kaolin Inert filler
79.64 Total 100.00
Example 11
TABLE-US-00023 Ingredients Function % w/w Permethrin Technical
Active Ingredient 5.32 POE of alkyl ether containing alkyl
Surfactant 2.75 phenol ethoxylate Calcium dodecyl benzene sulfonate
Surfactant 0.83 Precipitated Silica Inert filler 4.00 Sodium
naphthalene sulfonate Wetting agent 5.00 Styrene acrylic copolymer
Dispersant 8.00 Dimethyl polysiloxane, 30% emulsion Defoamer 0.50
Homopolymer of Vinylpyrrolidone Binder 0.25 Kaolin Inert filler
73.35 Total 100.00
Example 12
TABLE-US-00024 Ingredients Function % w/w Permethrin Technical
Active Ingredient 31.92 POE of alkyl ether containing alkyl
Surfactant 2.75 phenol ethoxylate Calcium dodecyl benzene sulfonate
Surfactant 0.83 Precipitated Silica Inert filler 10 Sodium
naphthalene sulfonate Wetting agent 5.00 Styrene acrylic copolymer
Dispersant 8.00 Dimethyl polysiloxane, 30% emulsion Defoamer 0.5
Homopolymer of Vinylpyrrolidone Binder 0.25 Kaolin Inert filler
40.75 Total 100.00
Example 13
TABLE-US-00025 Ingredients Function % w/w Permethrin Technical
Active Ingredient 37.24 POE of alkyl ether containing alkyl
Surfactant 2.75 phenol ethoxylate Calcium dodecyl benzene sulfonate
Surfactant 0.83 Precipitated Silica Inert filler 12 Sodium
naphthalene sulfonate Wetting agent 4.00 Styrene acrylic copolymer
Dispersant 7.00 Dimethyl polysiloxane, 30% emulsion Defoamer 0.5
Homopolymer of Vinylpyrrolidone Binder 0.25 Kaolin Inert filler
35.43 Total 100.00
Example 14
TABLE-US-00026 Ingredients Function % w/w Permethrin Technical
Active Ingredient 42.56 POE of alkyl ether containing alkyl
Surfactant 2.75 phenol ethoxylate Calcium dodecyl benzene sulfonate
Surfactant 0.83 Precipitated Silica Inert filler 12 Sodium
naphthalene sulfonate Wetting agent 4.00 Styrene acrylic copolymer
Dispersant 7.00 Dimethyl polysiloxane, 30% emulsion Defoamer 0.5
Homopolymer of Vinylpyrrolidone Binder 0.25 Kaolin Inert filler
30.11 Total 100.00
Example 15
TABLE-US-00027 Ingredients Function % w/w Permethrin Technical
Active Ingredient 47.88 POE of alkyl ether containing alkyl
Surfactant 2.75 phenol ethoxylate Calcium dodecyl benzene sulfonate
Surfactant 0.83 Precipitated Silica Inert filler 20.0 Sodium
naphthalene sulfonate Wetting agent 3.0 Styrene acrylic copolymer
Dispersant 6.0 Dimethyl polysiloxane, 30% emulsion Defoamer 0.5
Homopolymer of Vinylpyrrolidone Binder 0.25 Kaolin Inert filler
18.79 Total 100.00
Example 16
TABLE-US-00028 Ingredients Function % w/w Permethrin Technical
Active Ingredient 53.20 POE of alkyl ether containing alkyl
Surfactant 2.75 phenol ethoxylate Calcium dodecyl benzene sulfonate
Surfactant 0.83 Precipitated Silica Inert filler 20.0 Sodium
naphthalene sulfonate Wetting agent 3.0 Styrene acrylic copolymer
Dispersant 6.00 Dimethyl polysiloxane, 30% emulsion Defoamer 0.5
Homopolymer of Vinylpyrrolidone Binder 0.25 Kaolin Inert filler
13.47 Total 100.00
The characteristic outcome of the employment of the process of the
proposed invention is the dispersing and wetting of almost 100% of
the particles with a minimum of water.
The Table 2 and 3 below show the advantages of the present
invention in terms of wettability, dispersibility &
suspensibility: i) Wettability time of less than 2 minutes,
preferably less than 1 minute; ii) Dispersibility of more than 60%,
preferably more than 70%; iii) Suspensibility of more than 60%,
preferably more than 75%; iv) Dustiness less than 1% w/w,
preferably less than 0.6% w/w.
TABLE-US-00029 TABLE 2 Sr. Comp. Comp. Comp. Comp. No. Ingredients
No. 8 No. 9 No. 10 No. 11 1 Appearance Cream Cream Cream Cream
colored colored colored colored free free free free flowing flowing
flowing flowing granules granule granule granule 2 Active content
(% w/w) 0.105 0.51 5.02 25.2 3 Suspensibility (% w/w) 94.20 93.89
92.50 87.50 4 Dispersibility (% w/w) 78 75 73 72 5 pH (1%
aq.solution) 7.65 7.55 7.45 7.40 6 Wet sieve (% retained on 0.12
0.11 0.13 0.11 75.mu. test sieve) 7 Wettability (sec.) 15 10 8 7 8
Dustiness (% w/w) 0.5 0.3 0.25 0.20
TABLE-US-00030 TABLE 3 Sr. Comp. Comp. Comp. Comp. Comp. No.
Ingredients No. 11 No. 12 No. 13 No. 14 No. 15 1 Appearance Cream
Cream Cream Cream Cream colored colored colored colored colored
free free free slightly slightly flowing flowing flowing sticky
sticky granule granule granule granules granules 2 Active content
30.12 35.02 40.15 45.17 50.14 (% w/w) 3 Suspensibility 78.25 72.00
65.00 60.00 57.00 (% w/w) 4 Dispersibility 72 70 65 62 60 (% w/w) 5
pH (1% 7.35 7.33 7.25 7.20 7.22 aq.solution) 6 Wet sieve 0.10 0.10
0.12 0.14 0.15 (% retained on 75.mu. test sieve) 7 Wettability
(sec.) 7 6 5 5 4 8 Dustiness (% 0.18 0.20 0.19 0.20 0.18 w/w)
The table 4 below shows the advantages of the present invention in
terms of storage stability:
TABLE-US-00031 TABLE 4 Batch No. 1 Batch No. 2 Batch No. 3 Cream
colored Cream colored Cream colored granules granules granules 7 14
7 14 7 14 Sr. Parameters 0 days days 0 days days 0 days days No.
Stage day AHS AHS day AHS AHS day AHS AHS 1 Active 25.87 25.83
25.84 25.87 25.83 25.84 25.54 25.81 25.41 content (% w/w) 2
Suspensibility 80.39 79.27 78.62 79.09 76.27 76.23 76.31 75.41
77.93 (% w/w) 3 Dispersibility 73 70 69 72 69 68 71 69 68 (% w/w) 4
pH 1% 7.40 7.45 7.43 7.32 7.25 7.24 7.28 7.27 7.30 aq.solution 5
Wet sieve 0.1 0.15 0.17 0.12 0.16 0.20 0.1 0.12 0.15 (% retained on
75 u test sieve) 6 Wettability 5 6 5 6 5 5 6 6 7 in sec. 7
Dustiness 0.20 0.21 0.18 0.18 0.20 0.19 0.21 0.20 0.22 (% w/w)
In addition to above, following are the further advantageous
features for the present invention: i) The process affords complete
control on the size of the granules produced. ii) The drying
temperature is also less, in-between 50 to 60.degree. C., leading
to energy savings as compared to conventional processes. iii) The
process does not require the grinding of the active ingredient
along with the inert ingredients. iv) The process affords multi
material processing leading to better solid and granulated product
of combined active ingredients. v) The process helps to convert the
liquid viscous pesticide into solid composition and product.
The present granular pesticidal formulation is used for controlling
pests. When the pesticidally active compound is an insecticidal
compound, they are preferably used for vegetables or fruit trees.
The present granular pesticidal formulation is used as water
dispersible granules, to be precise; the present granular
pesticidal formulation is diluted with water and then applied to
crop, soil or the like with a sprayer or the like.
Although this invention has been described with respect to specific
embodiments, the details thereof are not to be construed as
limitations, for it will be apparent that various equivalents,
changes and modifications may be resorted to without departing from
the spirit and scope of this invention. It is understood that such
equivalent embodiments are intended to be included within the scope
of this invention.
* * * * *
References